--- In dmcnews@xxxxxxxxxxxxxxx, "therealdmcvegas" <DMCVegas@xxxx> wrote: > Once again, I have failed my annual smog test! 935 HCppm @ idle, and 1135 > @ 2500 RPMs. ..... > > Any help, or at least ideas would be greatly appriciated! > > -Robert > vin 6585 "X" Hi Robert. These points come to mind. Normally I only pass on hard data, but since you specifically asked for help, or at least ideas, here goes. 1. The car should be warmed up, so the catalytic convertor is up to temperature. The warmup period is useful in purging the hydrocarbons in the charcoal canister, too. The longer the car waits between getting it to the station and putting it in the test bed, the more impact the cooling of the catalytic converter will have. There is data to support this. I don't have it. 2. Changing the oil immediately before testing supposedly helps, by dissolving the free hydrocarbons. I've heard this many times, but seen no data. 3. This is just my own speculation: I should think that a gasoline with a higher percentage of MtBE, which, as an ether, contains oxygen, would cause more complete combustion of the hydrocarbons (this is, after all, what this additive is intended to do). This being so, one could fill up the tank with premium, which tends to have more MtBE, unless you're in California. This should reduce the hydrocarbon content of the exhaust. Good luck. Rick